Florida State Road 84

State Road 84 (SR 84) is a highway in the U.S. state of Florida originally extending from Tamiami Trail (U.S. Route 41) in Naples to U.S. Route 1 in Fort Lauderdale. The road consists of two noncontiguous pieces––in Collier County as Davis Boulevard and in Broward County as Marina Mile Boulevard and highway frontage roads.

Collier County segment
A 7-mile-long section exists in Collier County, Florida, beginning at Tamiami Trail (US 41) in Naples. It travels east along Davis Boulevard, passing through the neighborhood of East Naples. This section has an eastern terminus at Collier Boulevard, where state maintenance of State Road 951 to the north transitions to the county as County Road 951 to the south, near Exit 101 of Interstate 75 (Alligator Alley) south of Golden Gate. East of SR / CR 951, the road is known as Beck Boulevard, a local road.

From 1969 until the completion of Interstate 75 in 1993, SR 84 was a primary route through Alligator Alley across the Florida peninsula.

Broward County segment
A 12-mile-long stretch in Broward County, Florida that is now primarily a service road for Interstate 595 (SR 862), with the westbound lanes adjacent to the New River Canal. The easternmost three miles (5 km) comprise a divided four-lane highway traversing a Fort Lauderdale neighborhood mostly known as Marina Mile Boulevard (though the most eastern mile of SR 84 is also known as Southeast 24th Street). The present I-595 follows the original route of SR 84 west of the split between the two roads.

History
In the 1960s, Tamiami Trail was becoming insufficient to handle the rapidly growing traffic between Tampa and South Florida, and adding lanes to the road that was once considered a major engineering feat was not feasible in light of the demands of nearby Everglades National Park and the Miccosukee Tribe living near the Trail. It was finally decided that a second transpeninsular road would be best to serve the need of motorists to go from “coast to coast” south of Lake Okeechobee, the new one featuring a toll limited access two-lane expressway, the "Everglades Parkway" (the original name of the road that became better known as “Alligator Alley”).

Construction began on Alligator Alley in the early 1960s. On the Naples side, the route would connect with Davis Boulevard, which was previously a local road running from US 41 to Airport Road (CR 31). Davis Boulevard was named for George Davis, one of the Naples area's first attorneys who built one of the first houses along the road near Shadowlawn Drive.

Maps in the late 1960s indicated that Alligator Alley would be designated State Road 838, a designation which runs along Sunrise Boulevard in Fort Lauderdale. Though, when the highway was completed and opened on February 11, 1968, the State Road 84 designation and signs were placed along the entire length of the road (101 mi) from Naples to Fort Lauderdale.

Two decades later, the southern extension of Interstate 75 from Tampa was moving forward with earnest, as was the construction of Interstate 595. Because the population and traffic of southern Broward County were growing at a fast rate, Interstate 595 was being built to improve the connections between the Alley and US 1 (and improve access to Port Everglades and Fort Lauderdale-Hollywood International Airport), and the eastbound lanes of SR 84 were shifted southward to accommodate the new expressway that runs down what once was a large grassy median with limited cross-overs/turnarounds for SR 84. I-595 was opened to traffic in the mid-1980s.

When four-laning of Alligator Alley was completed to Interstate highway and environmental standards (several tunnels were constructed at various points under the road for the critically endangered Florida Panther), signs along the toll road identifying it as SR 84 were removed, and I-75 signs went up to replace them in early 1993. While the SR 84 could have remained the hidden designation of the road, the Florida Department of Transportation decided to supersede it with the hidden designation already in place for I-75 in most of the state: SR 93. This created the disconnection of SR 84 that exists to the present day.